All new Clerk.js 2 Designs for Search Pages come with a Load More Results button included.
However if you are using an older version of the Designs, you can easily add it afterwards.
This is the code you need:
{% if hits > products.length %}
<div class="clerk-load-more-button" onclick="Clerk('content', '#{{ content.id }}', 'more', 40);">Show More Results</div>
{% endif %}
Simply paste this code in the bottom of HTML in your Search Page design:
You can even choose how many new products you want to load when the button is clicked by changing the number 40 to any other number. For example 60:
'#{{ content.id }}', 'more', 60)